The gorebrute ability is supposed to be just the double damage of the charging gore. I could include a base gore, then double the damage for a charge, though. That would be a nice benefit with the knockdown.
Armorhide DR would be fun.
Blindsight is pretty powerful compared to the rest of these.
Swiftstride is supposed to be more of a fast, lightwieght runner. Like a deer rather than a bull. I could see maybe putting trample into gorebrute.
But yeah, I could see throwing on an addendum to wallstride.